Field of the Invention
The present invention relates to an image processing apparatus and image processing method adapted to extract a unique portion of an inspection object, such as a defect.
Description of the Related Art
Japanese Patent Laid-Open No. 2013-185862 or ““KIZUKI” Algorithm inspired by Peripheral Vision and Involuntary Eye Movement”, Journal of the Japan Society for Precision Engineering, Vol. 79, No. 11, 2013, p. 1045-1049 discloses an algorism for detecting a defect of an inspection object in accordance with a human visual mechanism. Specifically, after imaging an inspection object, the resulting image is divided into division areas having a predetermined size, and averaging and quantization are performed on each of the division areas. In addition, in multiple cases where the size and/or phase of a division area are changed, such a process is performed, and from a result of adding the resulting quantized values, the presence or absence of a defect is determined, and if present, the position of the defect is also determined. By employing such a method, a defect of an inspection object can be efficiently extracted and made apparent without any human observation.
Also, Japanese Patent Laid-Open No. 2010-111031 discloses a method that when an inspection object is printed matter by an inkjet printing apparatus, suppresses a processing load on inspection and a reduction in inspection speed by first extracting a solid area where a defect specific to the printing apparatus is easily extracted, and inspecting the solid area.
However, when employing the algorithm disclosed in Japanese Patent Laid-Open No. 2013-185862 or the above-described Journal of the Japan Society for Precision Engineering, although a unique portion can be extracted from a uniform image, when attempting to extract a unique portion from an actually printed image, a unique portion present in original image data is also simultaneously detected. In order to avoid this, the method disclosed in Japanese Patent Laid-Open No. 2010-111031 can be also employed to inspect only a solid area; however, in this case, a defect inconspicuous in a solid area cannot be extracted.